In spinning Hall sensors, in particular vertical Hall sensors, an undesired residual offset after spinning is observed. This offset is caused primarily by nonlinear voltage-dependent resistors in the Hall plate and is known as the “junction-field effect” or “backbias effect” of the Hall plates.
Referring to FIG. 1, conventional efforts to address the residual offset include 90-degree parallel switching of the Hall plates (FIG. 1A), with a biasing voltage or current applied in each spinning phase and a differential voltage or current read as output (FIG. 1B). Such a “forced symmetry” approach, however, reduces but does not eliminate the offset. This is true in particular with respect to vertical Hall plates, which are asymmetrical in different spinning phases, though it applies as well to lateral Hall plates having a mismatch in the Hall plate itself and/or local stress effects.